A drastic need exists for increased sources of energy including electrical energy worldwide. In satisfying this urgent need, various related economic and ecological considerations must be borne in mind so that research and development activities will be in the proper direction for the maximum welfare of human society. For example, in the production of increased electrical energy, care must be exercised not to further pollute the atmosphere and to pollute waterways including pollution by heating above acceptable levels.
With all of this in mind, the creation of more economical and more efficient hydroelectric power plants appears to be highly desirable in satisfying the demand for more electrical energy. The present invention is directly concerned with this objective.
This invention relates to improvements in hydroelectric power generation systems, which ordinarily utilize channeled headwater of a dam to provide energy which drives turbines to power electric generators. Rate of flow of water to the dam site, being a natural phenomenon, is one of the unalterable factors which predetermines the amount of power which can be generated from the available headwaters. The head (height) of water at the dam is the other principle factor which determines the available power output of the turbine driven electric generators. The head is predetermined basically by the height of the dam; that being a controllable factor. Every dam site, for varying reasons however, imposes its limitations as to the practical height of that particular dam, even though, ideally and generally speaking, the higher the dam the more power it is theoretically capable of generating and, consequently, the more productive it is. Even at those sites where a high dam is possible to construct, funds available for dam construction frequently limit its height to something below the optimum, due to the fact that the cost of a dam increases sharply as its height increases. Where construction cost is not the prime determining factor, dam height at a strategic or a particularly desirable site may be limited by the topography and/or other uncontrollable or undesirable conditions, resulting in inadequate power output. The remedy could be a costly one, entailing the construction of one or more dams further downstream to make up the desired power.
To remedy the situation and achieve the desired increase in hydroelectric power generation, the present invention utilizes a novel process and sound engineering principles to artificially create the maximum obtainable head of water at any dam site, with values substantially in excess of those which the height of the dam alone would be capable of producing, if unaided or unmodified, as by increasing its height. Fundamentally, this increased head is obtained by locating turbines in a dry pit near the dam, and well below the bed level of the tailwater, together with novel means for continuously removing water discharged by the turbine means and elevating this water to ground level, where it forms or joins the tailwater of the dam, by means of one or more self-energizing impulse pumps known in the art as hydraulic rams.
Through this means, the total effective working head of the system equals the sum of the head of the dam, and the head created by the vertical drop from ground level to the sub-surface location of the turbine means. Doubling of the dam's effective head through this device is not only entirely feasible and practical but highly advantageous from an economic standpoint.
Ordinarily, to locate turbines below ground or stream bed level is impractical, or more accurately, not workable due to the fact that turbine discharge will quickly fill the pit, thus nullifying the would-be beneficial effect of the added head created by the subterranean location of the turbine means. To make it operate, the turbine pit would require continuous drainage by massive pumps utilizing auxiliary power which would consume more energy than the dam would be capable of producing. This is one of the reasons why this system has heretofore not been developed.
The present invention, however, renders the desired system entirely practical and economical to construct and maintain, and achieves the desired end of greatly increasing the effective head of any dam of predetermined fixed height and without increasing the height of the dam. The invention thus, in effect, converts low dams into high dams, allowing them to utilize for maximum efficiency impulse type turbines which are generally less expensive and easier to maintain. Conventional low dams, unless their power output potential is enhanced by a large natural supply of water, must use a more costly and less efficient, higher maintenance type of turbine, as is well known. Additionally, by means of the invention, many relatively small, natural water sources which would ordinarily be passed over as feasible dam sites for hydroelectric power production, will now become practical power generating sites for minimal construction costs.
Other features and advantages of the invention will become apparent during the course of the following detailed description.